From: Johannes Berg <johannes@sipsolutions.net>
To: Christoph Hellwig <hch@infradead.org>,
Benjamin Berg <benjamin@sipsolutions.net>
Cc: linux-um@lists.infradead.org, "Willy Tarreau" <w@1wt.eu>,
"Thomas Weißschuh" <linux@weissschuh.net>,
linux-kselftest@vger.kernel.org,
"Arnaldo Carvalho de Melo" <acme@redhat.com>,
linux-kernel@vger.kernel.org,
"Benjamin Berg" <benjamin.berg@intel.com>
Subject: Re: [PATCH v2 00/11] Start porting UML to nolibc
Date: Mon, 22 Sep 2025 09:41:36 +0200 [thread overview]
Message-ID: <4354d88c2ff7a57a7324cc39b4ce5ed4ebe5277d.camel@sipsolutions.net> (raw)
In-Reply-To: <aM15eChUObXfxLzs@infradead.org>
On Fri, 2025-09-19 at 08:40 -0700, Christoph Hellwig wrote:
> On Fri, Sep 19, 2025 at 05:34:09PM +0200, Benjamin Berg wrote:
> > From: Benjamin Berg <benjamin.berg@intel.com>
> >
> > This patchset is an attempt to start a nolibc port of UML.
>
> It would be useful to explain why that is desirable.
Agree, it should be here, but FWIW it's been discussed elsewhere on the
linux-um list in the past and basically there are various issues around
it. Off the top of my head:
- glibc enabling new features such as rseq that interact badly with how
UML manages memory (there were fixes for this, it worked sometimes
and sometimes not)
- allocation placement for TLS is problematic (see the SMP series)
- it's (too) easy to accidentally call glibc functions that require
huge amounts of stack space
There are probably other reasons, but the mixed nature of UML being both
kernel and "hypervisor" code in a single place doesn't mix well with
glibc.
johannes
next prev parent reply other threads:[~2025-09-22 7:41 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-09-19 15:34 [PATCH v2 00/11] Start porting UML to nolibc Benjamin Berg
2025-09-19 15:34 ` [PATCH v2 01/11] tools compiler.h: fix __used definition Benjamin Berg
2025-09-19 15:34 ` [PATCH v2 02/11] um: use tools/include for user files Benjamin Berg
2025-09-19 15:34 ` [PATCH v2 03/11] tools/nolibc/stdio: remove perror if NOLIBC_IGNORE_ERRNO is set Benjamin Berg
2025-09-21 7:55 ` Willy Tarreau
2025-09-21 16:37 ` Thomas Weißschuh
2025-09-21 17:05 ` Benjamin Berg
2025-09-21 17:13 ` Willy Tarreau
2025-09-21 17:16 ` Benjamin Berg
2025-09-21 17:23 ` Willy Tarreau
2025-09-21 18:26 ` Thomas Weißschuh
2025-09-21 18:28 ` Willy Tarreau
2025-09-21 17:09 ` Willy Tarreau
2025-09-19 15:34 ` [PATCH v2 04/11] tools/nolibc/dirent: avoid errno in readdir_r Benjamin Berg
2025-09-19 15:34 ` [PATCH v2 05/11] tools/nolibc: use __fallthrough__ rather than fallthrough Benjamin Berg
2025-09-19 15:34 ` [PATCH v2 06/11] tools/nolibc: add option to disable runtime Benjamin Berg
2025-09-20 9:08 ` Thomas Weißschuh
2025-09-19 15:34 ` [PATCH v2 07/11] um: add infrastructure to build files using nolibc Benjamin Berg
2025-09-21 8:13 ` Willy Tarreau
2025-09-22 7:11 ` Berg, Benjamin
2025-09-19 15:34 ` [PATCH v2 08/11] um: use nolibc for the --showconfig implementation Benjamin Berg
2025-09-19 15:34 ` [PATCH v2 09/11] tools/nolibc: add uio.h with readv and writev Benjamin Berg
2025-09-20 9:11 ` Thomas Weißschuh
2025-09-19 15:34 ` [PATCH v2 10/11] tools/nolibc: add ptrace support Benjamin Berg
2025-09-20 9:27 ` Thomas Weißschuh
2025-09-21 8:19 ` Willy Tarreau
2025-09-19 15:34 ` [PATCH v2 11/11] um: switch ptrace FP register access to nolibc Benjamin Berg
2025-09-19 20:50 ` kernel test robot
2025-09-19 15:40 ` [PATCH v2 00/11] Start porting UML " Christoph Hellwig
2025-09-22 7:41 ` Johannes Berg [this message]
2025-09-23 23:58 ` Hajime Tazaki
2025-09-24 3:32 ` Willy Tarreau
2025-09-24 7:55 ` Benjamin Berg
2025-09-25 1:05 ` Hajime Tazaki
2025-09-20 9:30 ` Thomas Weißschuh
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